I would like to mention Williams Soaring Center. http://www.williamssoaring.com/ (no affiliation) Not sure if they are open 7 days in summer. Only aerotows, but. Best glider fleet I've encountered in the US so far. Great web site that's very comprehensive and connected with the Valley Soaring Association web site which is loaded with great information.

They have a free bunk room with bathroom, new kitchen, plus the town of Williams is very cheap to stay and eat. Part of my stay was at a great little hotel for 45USD a night and the meals at a great taco stand for about 6 bucks. My instructor Ed was fantastic. Great friendly staff, beautiful mountains 10 miles to the west to suppliment the valley thermal soaring.

Major airport at Sacramento California that I flew into from Michigan. It's about a 50 minute drive from Sacramento to Williams I think.

Here is a short video of my recent visit. Minden also great spot.

http://www.youtube.com/watch?v=DHSXNqOc1Nw&sns=em

Aaron Kiley